Flurbiprofen derivatives as novel α-amylase inhibitors: Biology-oriented drug synthesis (BIODS), in vitro, and in silico evaluation

Phytochemical Profiling and Biological Evaluation of Dianthus sylvestris subsp. aristidis: A Chromatographic and Mass Spectrometry Approach to Uncovering Bioactive Metabolites for Dermatological and Metabolic Disorder Management

Background/Objectives: This study provides the first comprehensive phytochemical composition and biological evaluation of Dianthus sylvestris subsp. aristidis (Batt.) Greuter & Burdet, a plant endemic to Algeria with unexplored pharmacological potential. The objective is to identify novel bioactive metabolites in the plant's extracts and assess their potential applications for skincare and metabolic disorder management, addressing gaps in the current understanding of its medicinal value. Methods: Liquid chromatography coupled with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) profiling was used to analyze the hydromethanolic (HMeOH) leaf extract and identify bioactive compounds. The biological activities of HMeOH, ethyl acetate (EtOAc), and butanolic (n-BuOH) extracts were tested for cytotoxicity using the brine shrimp lethality test, photoprotective potential by calculating the sun protection factor (SPF), and enzymatic inhibitory activities against alpha-amylase, urease, and tyrosinase. Results: The LC-ESI-MS/MS profiling of the MeOH extract identified 22 bioactive compounds, including phenolic acids and flavonoids, some of which have not been previously reported in this species. Cytotoxicity tests showed that all extracts were non-toxic (half-lethal concentration (LC50) > 100 micrograms per milliliter). The SPF values indicated significant photoprotective potential, with EtOAc (SPF = 45.19 ± 0.73) and n-BuOH (SPF = 43.81 ± 0.59) extracts showing high sun protection activity. The n-BuOH extract exhibited strong alpha-amylase inhibitory activity (half-maximal inhibitory concentration (IC50) = 307.08 micrograms per milliliter), surpassing the standard acarbose (IC50 = 3650.93 micrograms per milliliter), suggesting potential applications in diabetes management. Conclusions: Dianthus sylvestris subsp. aristidis demonstrates significant pharmacological potential as a source of bioactive secondary metabolites for skincare and metabolic disorder management. These findings provide new insights into the plant's therapeutic potential and set a foundation for future pharmacological and clinical investigations.

Synthesis, Urease Inhibitory Activity, Molecular Docking, Dynamics, MMGBSA and DFT Studies of Hydrazone-Schiff Bases Bearing Benzimidazole Scaffold

In this study, eleven hydrazone-Schiff bases bearing benzimidazole moiety were synthesized successfully via three step reactions and structures of these products were deduced by HR-ESI-MS, 1H-, and 13C-NMR spectroscopic techniques. Lastly, these derivatives were tested for their in vitro urease inhibitory potential. Six compounds among the series attributed excellent inhibition with IC50 values of 7.20±0.59 to 19.61±1.10 μM better than the reference drug thiourea (IC50=22.12±1.20 μM). Similarly, three derivatives showed significant while two compounds showed less inhibitory effects against the urease enzyme. The molecular docking analysis was carried out to reveal the binding modes and types of interaction taking place between protein (urease) and synthesized compounds. The Density Functional Theory (DFT) calculations were performed at B3LYP/6-311++G(d,p) to check the structure stability. For the account of intramolecular interaction, the DFT-D3 and Reduced Density Gradient (RDG) analysis were performed. Furthermore, the chemical nature of all compounds was explored by TD-DFT method using CAM-B3LYP functional with 6-311++G(d,p) basis set. The dynamic simulation as well as MMGBSA studies validated the binding affinity and stability of the ligand receptor complex, displaying main interactions contributing in the biological activity of the product derivatives.

Exploring the Versatility of Azine Derivatives: A Comprehensive Review on Synthesis and Biological Applications

Organic compounds containing azines, di-imines, or bis-Schiff-bases have two azomethine (-CH=N-) functional groups associated with a bridging component. These constituents have attracted attention from a diversity of disciplines, comprising coordination, medicinal, agriculture chemistry, and organic synthesis, because of their comprehensive chemical reactivity and nature. This study determines common synthetic approaches and various biological and pharmacological activities of several substituted bis-Schiff byproducts. The usefulness of bis-Schiff bases in synthetic chemistry and their potential as inhibitors of a number of enzymes have attracted research attention. We have examined different biological activities and common synthetic methods used to make bis- Schiff bases that have been published in the literature. A systematic search of the literature has been performed, and studies fitting the prearranged inclusion standards have been inspected. This review can open up new potentials for upcoming research in this area and advance our information on bis- Schiff bases.

Exploring new 5-Nitroimidazole Derivatives as Potent Acetylcholinesterase and Butyrylcholinesterase Enzyme Inhibitors

Discovering new compounds capable of inhibiting physiologically and metabolically significant drug targets or enzymes is of paramount importance in biological chemistry. With this aim, new 5-nitroimidazole derivatives (1-4) were designed and synthesized, and their inhibitory activities against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) were discovered using acetyl (butyryl) thiocholine and Ellman's reagents for spectrophotometric assay. The inhibitory profiles of the synthesized compounds were assessed by comparing their IC50 and Ki values. Results demonstrate significant inhibitory activity of all synthesized compounds against both AChE and BuChE compared to the reference compound, donepezil. Notably, compound 4 exhibited dual inhibition of these enzymes, showing the highest activity against Electrophorus electricus AChE (EeAChE) with a Ki value of 0.024±0.009 nM and against equine BuChE (eqBuChE) with a Ki value of 0.087±0.017 nM. Furthermore, molecular modeling was conducted to study the interaction modes of the most potent compound (4) and donepezil in the active site of their related enzymes' crystal structures (PDB ID: 4EY7 and 4BDS, respectively). Additionally, drug-likeness, ADME, and toxicity profiles of the compounds and metronidazole were predicted. The above results indicated that the dual inhibition of these enzymes is considered as a promising strategy for the treatment of neurological disorder especially Alzheimer's disease.

Synthesis of Flurbiprofen Based Amide Derivatives as Potential Leads for Diabetic Management: In Vitro α‐glucosidase Inhibition, Molecular Docking and DFT Simulation Approach

This research is based on the synthesis, characterization and in vitro α‐glucosidase inhibitory activity of fourteen amides (2 a–2 n) of flurbiprofen drug. Seven compounds in the series displayed potent inhibitory activity having IC50 values (IC50=5.67±0.89 μM) to (IC50=17.87±2.39 μM) in comparison with acarbose standard (IC50=875.75±1.24 μM). The FMO of 2 a–2 n molecules was quantified by the DFT assay. The promising value for energygap explained the higher poteny agannist α‐glucosidase. MEP provides the insights into the distribution of electrostatic potential on the molecular surface of 2 a–2 n, showing that C=O group has the highest negative potential. The AIM investigation revealed minimal hydrogen bond energy and non‐covalent interactions. This suggests that these molecules may have limited hydrogen bonding and non‐covalent interactions, which could be relevant to their chemical behavior. Molecular docking and (MEP) showed the C=O group, with its high negative potential, is a key in recognizing the catalytic non‐polar regions of enzymes, such as TYR72, GLU277, and ARG442. Similarly, the hydrophobic regions of investigated compounds play a significant role in identifying essential amino acids like ASP352 and ARG442, which are vital for the ligand's proper orientation and subsequent biological activity.

Pyrano[2,3-b]chromone derivatives as novel dual inhibitors of α-glucosidase and α-amylase: Design, synthesis, biological evaluation, and in silico studies

Inhibition of α-glucosidase and α-amylase is an important target for treatment of type 2 diabetes. In this work, a novel series of pyrano[2,3-b]chromene derivatives 5a-m was designed based on potent α-glucosidase and α-amylase inhibitors and synthesized by simple chemical reactions. These compounds were evaluated against the latter enzymes. Most of the title compounds exhibited high inhibitory activity against α-glucosidase and α-amylase in comparison to standard inhibitor (acarbose). Representatively, the most potent compound, 4-methoxy derivative 5d, was 30.4 fold more potent than acarbose against α-glucosidase and 6.1 fold more potent than this drug against α-amylase. In silico molecular modeling demonstrated that compound 5d attached to the active sites of α-glucosidase and α-amylase with a favorable binding energies and established interactions with important amino acids. Dynamics of compound 5d also showed that this compound formed a stable complex with the α-glucosidase active site. In silicodrug-likeness as well as ADMET prediction of this compound was also performed and satisfactory results were obtained.

Rhodanine-benzamides as potential hits for α-amylase enzyme inhibitors and radical (DPPH and ABTS) scavengers

A series of 3-substituted and 3,5-disubstituted rhodanine-based derivatives were synthesized from 3-aminorhodanine and examined for α-amylase inhibitory, DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities in vitro. These derivatives displayed significant α-amylase inhibitory potential with IC50 values of 11.01-56.04 µM in comparison to standard acarbose (IC50 = 9.08 ± 0.07 µM). Especially, compounds 7 (IC50 = 11.01 ± 0.07 µM) and 8 (IC50 = 12.01 ± 0.07 µM) showed highest α-amylase inhibitory activities among the whole series. In addition to α-amylase inhibitory activity, all compounds also demonstrated significant scavenging activities against DPPH and ABTS radicals, with IC50 values ranging from 12.24 to 57.33 and 13.29-59.09 µM, respectively, as compared to the standard ascorbic acid (IC50 = 15.08 ± 0.03 µM for DPPH; IC50 = 16.09 ± 0.17 µM for ABTS). These findings reveal that the nature and position of the substituents on the phenyl ring(s) are crucial for variation in the activities. The structure-activity relationship (SAR) revealed that the compounds bearing an electron-withdrawing group (EWG) at para substitution possessed the highest activity. In kinetic studies, only the km value was changed, with no observed changes in Vmax, indicating a competitive inhibition. Molecular docking studies revealed important interactions between compounds and the α-amylase active pocket. Further advanced research needs to perform on the identified compounds in order to obtain potential antidiabetic agents.

Biooriented Synthesis of Ibuprofen-Clubbed Novel Bis-Schiff Base Derivatives as Potential Hits for Malignant Glioma: In Vitro Anticancer Activity and In Silico Approach

This research work is based on the synthesis of bis-Schiff base derivatives of the commercially available ibuprofen drug in outstanding yields through multistep reactions. Structures of the synthesized compounds were confirmed by the help of modern spectroscopic techniques including high-resolution electrospray ionization mass spectrometry (HR-ESI-MS), 1H NMR, and 13C NMR. The synthesized compounds were evaluated for their anticancer activity using a normal human embryonic kidney HEK293 cell and U87-malignant glioma (ATCC-HTB-14) as a cancer cell line. All of the synthesized compounds among the series exhibited excellent to less antiproliferative activity having IC50 values ranging from 5.75 ± 0.43 to 150.45 ± 0.20 μM. Among them, compound 5e (IC50 = 5.75 ± 0.43 μM) was found as the most potent antiprolifarative agent, while 5f, 5b, 5a, 5n, 5r, 5s, 5g, 5q, 5i, and 5j exhibited good activity with IC50 values from 24.17 ± 0.46 to 43.71 ± 0.07 μM. These findings suggest that these cells (HEK293) are less cytotoxic to the activities of compounds and increase the cancer cell death in brain, while the lower cytotoxicity of the potent compounds in noncancerous cells suggests that these derivatives will provide promising treatment for patients suffering from brain cancer. The results of the docking study exposed a promising affinity of the active compounds toward casein kinase-2 enzyme, which shows green signal for cancer treatment.

Exploring the synthesis, structure, spectroscopy and biological activities of novel 4-benzylidene-1-(2-(2,4-dichloro phenyl)acetyl) thiosemicarbazide derivatives: An integrated experimental and theoretical investigation

BACKGROUND

Novel α-amylase inhibitors play a crucial role in managing diabetes and obesity, contributing to improved public health by addressing these challenging and prevalent conditions. Moreover, the synthesis of anti-oxidant agents is essential due to their potential in combating oxidative stress-related diseases and promoting overall health.

OBJECTIVE

Synthesis of thoisemicarbazone derivatives of 2,4-dichlorophenyl acetic acid and to screened them for their biological activities.

METHOD

Thiosemicarbazone derivatives (4-13) were synthesized by refluxing 2,4-dichlorophenyl acetic acid with sulfuric acid in ethanol to get the ester (2), which was further refluxed with thiosemicarbazide to get compound (3). Finally, different aromatic aldehydes were refluxed with compound (3) in ethanol in catalytic amount of acetic acid to obtained the final products (4-13). Using modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR, the structures of the created derivatives were confirmed.

RESULTS

The synthesized derivatives showed excellent to good inhibitory activity in the range of IC50 values of 4.95 ± 0.44 to 69.71 ± 0.05 µM against α-amylase enzyme when compared to standard drug acarbose (IC50 = 21.55 ± 1.31 µM). In case of iron chelating activity, these products showed potent activity better than standard EDTA (IC50 = 66.43 ± 1.07 µM) in the range of IC50 values of 22.43 ± 2.09 to 61.21 ± 2.83 µM. However, the obtained products also show excellent to good activity in the range of IC50 values of 28.30 ± 1.17 to 64.66 ± 2.43 µM against hydroxyl radical scavenging activity when compared with standard vitamin C (IC50 = 60.51 ± 1.02 µM). DFT used to calculate different reactivity factors including ionization potential, electronegativity, electron affinity, chemical softness, and chemical hardness were calculated using frontier molecular orbital (FMO) computations. The molecular docking studies for the synthesized derivatives with α-amylase were carried out using the AutoDock Vina to understand the binding affinities with active sites of the protein.

Discovery of (S)-flurbiprofen-based novel azine derivatives as prostaglandin endoperoxide synthase-II inhibitors: Synthesis, in-vivo analgesic, anti-inflammatory activities, and their molecular docking

The anti-inflammatory and analgesic drugs currently used are associated with several adverse effects and found to be highly unsafe for long-term use. Currently, nineteen novel bis-Schiff base derivatives (1-19) of flurbiprofen have been designed, prepared and assessed for in-vivo analgesic, anti-inflammatory and in vivo acute toxicity evaluation. The structures of the acquired compounds were deduced through modern spectroscopic techniques including HR-ESI-MS, 13C-, and 1H NMR. Amongst the series, compounds 7, 9, and 10 attributed potent activities with 93.89, 92.50, and 90.47% decreased edema, respectively compared to flurbiprofen (90.01%), however, compounds 11 and 15 exhibited significant activity of 90.00% decrease. Out of them, fourteen compounds (1-6, 8, 12-14, and 16-19) displayed good activity in the range of 68.96-86.95%. In case of an analgesic study, all the derivatives significantly (p 0.001) increased the pain threshold time particularly compound 7 had the best analgesic effect (24 ± 2.08 s) in comparison with flurbiprofen (21.66 ± 2.02 s) using hot plate test. Similarly, in the acetic acid-induced writhing test, compound 7 determined a potent inhibitory effect (60.47 %) close to flurbiprofen (59.28%). All the synthesized derivatives were found safe up to the dose of 30 mg/kg, in acute toxicity study. On a molecular scale, the synthesized compounds were modeled through a ligand-based pharmacophore study and molecular docking to have insight into the different possible interactions leading to high inhibition levels against the COX-2 enzyme.

Novel flurbiprofen clubbed oxadiazole derivatives as potential urease inhibitors and their molecular docking study

In this study, twenty eight novel oxadiazole derivatives (5-32) of the marketed available non-steroidal anti-inflammatory drug (NSAID), (S)-flurbiprofen (1), were synthesized via I2 mediated cyclo-addition reaction in better yields. The synthesized hydrazone-Schiff bases were cyclized with iodine by using potassium hydroxide as a base in DMSO solvent to obtain oxadiazole derivatives (5-32). Structures of the synthesized products were confirmed with HR-ESI-MS, 1H-NMR spectroscopy and CHN analysis. After structure confirmations all analogs were evaluated for urease (in vitro) inhibitory activity. Amongst the series, fourteen compounds 20, 26, 30, 24, 21, 16, 28, 31, 32, 7, 19, 13, 10, and 6 were found to be excellent inhibitors of urease enzyme, having IC50 values of 12 ± 0.9 to 20 ± 0.5 μM, better than the standard thiourea (IC50 = 22 ± 2.2 μM), whereas the remaining fourteen derivatives displayed good to moderate activity. The in silico study was executed to analyse the interaction between the active site of the enzyme (urease) and the produced compounds. The docking study revealed that compounds 20, 26, 30, 24, 21, 16, 28, 31, 32, 7, 19, 13, 10, and 6 had lower docking scores than the standard compound thiourea and revealed better interactions with the urease enzyme.

Synthesis, molecular structure and urease inhibitory activity of novel bis-Schiff bases of benzyl phenyl ketone: A combined theoretical and experimental approach

Background

Urease belongs to the family of amid hydrolases with two nickel atoms in their core structure. On the basis of literature survey, this research work is mainly focused on the study of bis-Schiff base derivatives of benzyl phenyl ketone nucleus.

Objective

Synthesis of benzyl phenyl ketone based bis-Schiff bases in search of potent urease inhibitors.

Method

In the current work, bis-Schiff bases were synthesized through two steps reaction by reacting benzyl phenyl ketone with excess of hydrazine hydrate in ethanol solvent in the first step to get the desired hydrazone. In last, different substituted aromatic aldehydes were refluxed in catalytic amount of acetic acid with the desired hydrazone to obtain bis-Schiff base derivatives in tremendous yields. Using various spectroscopic techniques including FTIR, HR-ESI-MS, and ¹H NMR spectroscopy were used to clarify the structures of the created bis-Schiff base derivatives.

Results

The prepared compounds were finally screened for their in-vitro urease inhibition activity. All the synthesized derivatives (3-9) showed excellent to less inhibitory activity when compared with standard thiourea (IC₅₀ = 21.15 ± 0.32 µM). Compounds 3 (IC₅₀ = 22.21 ± 0.42 µM), 4 (IC₅₀ = 26.11 ± 0.22 µM) and 6 (IC₅₀ = 28.11 ± 0.22 µM) were found the most active urease inhibitors near to standard thiourea among the synthesized series. Similarly, compound 5 having IC₅₀ value of 34.32 ± 0.65 µM showed significant inhibitory activity against urease enzyme. Furthermore, three compounds 7, 8, and 9 exhibited less activity with IC₅₀ values of 45.91 ± 0.14, 47.91 ± 0.14, and 48.33 ± 0.72 µM respectively. DFT used to calculate frontier molecular orbitals including; HOMO and LUMO to indicate the charge transfer from molecule to biological transfer, and MEP map to indicate the chemically reactive zone suitable for drug action. The electron localization function (ELF), non-bonding orbitals, AIM charges are also calculated. The docking study contributed to the analysis of urease protein binding.

New Acetamide-Sulfonamide-Containing Scaffolds: Antiurease Activity Screening, Structure-Activity Relationship, Kinetics Mechanism, Molecular Docking, and MD Simulation Studies

The development of novel scaffolds that can increase the effectiveness, safety, and convenience of medication therapy using drug conjugates is a promising strategy. As a result, drug conjugates are an active area of research and development in medicinal chemistry. This research demonstrates acetamide-sulfonamide scaffold preparation after conjugation of ibuprofen and flurbiprofen with sulfa drugs, and these scaffolds were then screened for urease inhibition. The newly designed conjugates were confirmed by spectroscopic techniques such as IR, 1HNMR, 13CNMR, and elemental analysis. Ibuprofen conjugated with sulfathiazole, flurbiprofen conjugated with sulfadiazine, and sulfamethoxazole were found to be potent and demonstrated a competitive mode of urease inhibition, with IC50 (µM) values of 9.95 ± 0.14, 16.74 ± 0.23, and 13.39 ± 0.11, respectively, and urease inhibition of 90.6, 84.1, and 86.1% respectively. Ibuprofen conjugated with sulfanilamide, sulfamerazine, and sulfacetamide, whereas flurbiprofen conjugated with sulfamerazine, and sulfacetamide exhibited a mixed mode of urease inhibition. Moreover, through molecular docking experiments, the urease receptor-binding mechanisms of competitive inhibitors were anticipated, and stability analysis through MD simulations showed that these compounds made stable complexes with the respective targets and that no conformational changes occurred during the simulation. The findings demonstrate that conjugates of approved therapeutic molecules may result in the development of novel classes of pharmacological agents for the treatment of various pathological conditions involving the urease enzyme.

Syntheses, in vitro, and in silico studies of rhodanine-based schiff bases as potential α-amylase inhibitors and radicals (DPPH and ABTS) scavengers

A two-step reaction method was used to synthesize a series of rhodanine-based Schiff bases (2-33) that were characterized using spectroscopic techniques. All compounds were assessed for α-amylase inhibitory and radical scavenging (DPPH and ABTS) activities. In comparison to the standard acarbose (IC50 = 9.08 ± 0.07 µM), all compounds demonstrated good to moderate α-amylase inhibitory activity (IC50 = 10.91 ± 0.08-61.89 ± 0.102 µM). Compounds also demonstrated significantly higher DPPH (IC50 = 10.33 ± 0.02-96.65 ± 0.03 µM) and ABTS (IC50 = 12.01 ± 0.12-97.47 ± 0.13 µM) radical scavenging activities than ascorbic acid (DPPH, IC50 = 15.08 ± 0.03 µM; ABTS, IC50 = 16.09 ± 0.17 µM). The limited structure-activity relationship (SAR) suggests that the position and nature of the substituted groups on the phenyl ring have a vital role in varying inhibitory potential. Among the series, compounds with an electron-withdrawing group at the para position showed the highest potency. Kinetic studies revealed that the compounds followed a competitive mode of inhibition. Molecular docking results are found to agree with experimental findings, showing that compounds reside in the active pocket due to the main rhodanine moiety.

Inclusion of Nitrofurantoin into the Realm of Cancer Chemotherapy via Biology-Oriented Synthesis and Drug Repurposing

Structural modifications of the antibacterial drug nitrofurantoin were envisioned, employing drug repurposing and biology-oriented drug synthesis, to serve as possible anticancer agents. Eleven compounds showed superior safety in non-cancerous human cells. Their antitumor efficacy was assessed on colorectal, breast, cervical, and liver cancer cells. Three compounds induced oxidative DNA damage in cancer cells with subsequent cellular apoptosis. They also upregulated the expression of Bax while downregulated that of Bcl-2 along with activating caspase 3/7. The DNA damage induced by these compounds, demonstrated by pATM nuclear shuttling, was comparable in both MCF7 and MDA-MB-231 (p53 mutant) cell lines. Mechanistic studies confirmed the dependence of these compounds on p53-mediated pathways as they suppressed the p53-MDM2 interaction. Indeed, exposure of radiosensitive prostatic cancer cells to low non-cytotoxic concentrations of compound 1 enhanced the cytotoxic response to radiation indicating a possible synergistic effect. In vivo antitumor activity was verified in an MCF7-xenograft animal model.

Synthesis and characterization of biologically active flurbiprofen amide derivatives as selective prostaglandin-endoperoxide synthase II inhibitors: In vivo anti-inflammatory activity and molecular docking

A novel series of twenty two flurbiprofen amides (1-22) were designed and synthesized in good to excellent yields by reacting flurbiprofen acid with various aromatic/aliphatic primary amines in the presence of 1,1‑carbonyldiimidazole (CDI) in basic medium using acetonitrile as solvent. Structures of the synthesized derivatives were elucidated with the help of HR-ESI-MS, ¹H-, and ¹³C NMR spectroscopy and finally screened them for their in-vivo anti-inflammatory potential using carrageenan induced mice paw oedema assay. Among the series, four compounds (8, 14, 15, and 20) displayed excellent activity ranging from 59.0 to 77.7 % decrease, while eight compounds (1, 3, 7, 10, 12, 13, 17, and 18) exhibited good activity in the decrease range of 37.0-50.0 %. Additionally, four compounds (2, 6, 16, and 22) attributed less activity, while the remaining six compounds (4, 5, 9, 11, 19, and 21) were found to be inactive. Furthermore, the In-silico studies were executed on the synthesized derivatives in order to explain the binding interface of compounds with the active sites of prostaglandin endoperoxide-synthase II enzyme.

Synthetic benzofuran-linked chalcones with dual actions: a potential therapeutic approach to manage diabetes mellitus

Background: Identification of molecules having dual capabilities to reduce postprandial hyperglycemia and oxidative stress is one of the therapeutic approaches to treat diabetes mellitus. In this connection, a library of benzofuran-linked chalcone derivatives were evaluated for their dual action. Methods: A series of substituted benzofuran-linked chalcones (2-33) were synthesized and tested for α-amylase inhibitory as well as 2,2-diphenylpicrylhydrazyl (DPPH) and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activities. Results: All compounds showed α-amylase inhibitory activity ranging from IC50 = 12.81 ± 0.03 to 87.17 ± 0.15 μM, compared with the standard acarbose (IC50 = 13.98 ± 0.03 μM). Compounds also demonstrated radical scavenging potential against DPPH and ABTS radicals. Conclusion: The identified compounds may serve as potential leads for further advanced research.

Synthetic Transformation of 2-{2-Fluoro[1,1'-biphenyl]-4-yl} Propanoic Acid into Hydrazide-Hydrazone Derivatives: In Vitro Urease Inhibition and In Silico Study

In the present study, 28 acyl hydrazones (4-31) of flurbiprofen were synthesized in good to excellent yield by reacting different aromatic aldehydes with the commercially available drug flurbiprofen. The compounds were deduced with the help of different spectroscopic techniques like ¹H-NMR and HREI-MS and finally evaluated for in vitro urease inhibitory activity. All of the synthesized products demonstrated good inhibitory activities in the range of IC₅₀ = 18.92 ± 0.61 to 90.75 ± 7.71 μM as compared to standard thiourea (IC₅₀ = 21.14 ± 0.42 μM). Compound 30 was found to be the most active among the series better than the standard thiourea. A structure-activity relationship (SAR) study revealed that the presence of electron-donating groups on the phenyl ring plays a prominent role in the inhibition of the urease enzyme. Moreover, in silico molecular modeling analysis was carried out to study the effect of substituents in synthesized derivatives on the binding interactions with the urease enzyme.

Synthesis of Novel Benzimidazole-Based Thiazole Derivatives as Multipotent Inhibitors of α-Amylase and α-Glucosidase: In Vitro Evaluation along with Molecular Docking Study

In this study, hybrid analogs of benzimidazole containing a thiazole moiety (1-17) were afforded and then tested for their ability to inhibit α-amylase and α-glucosidase when compared to acarbose as a standard drug. The recently available analogs showed a wide variety of inhibitory potentials that ranged between 1.31 ± 0.05 and 38.60 ± 0.70 µM (against α-amylase) and between 2.71 ± 0.10 and 42.31 ± 0.70 µM (against α-glucosidase) under the positive control of acarbose (IC₅₀ = 10.30 ± 0.20 µM against α-amylase) (IC₅₀ = 9.80 ± 0.20 µM against α-glucosidase). A structure-activity relationship (SAR) study was carried out for all analogs based on substitution patterns around both rings B and C respectively. It was concluded from the SAR study that analogs bearing either substituent(s) of smaller size (-F and Cl) or substituent(s) capable of forming hydrogen bonding (-OH) with the catalytic residues of targeted enzymes enhanced the inhibitory potentials. Therefore, analogs 2 (bearing meta-fluoro substitution), 3 (having para-fluoro substitution) and 4 (with ortho-fluoro group) showed enhanced potency when evaluated against standard acarbose drug with IC₅₀ values of 4.10 ± 0.10, 1.30 ± 0.05 and 1.90 ± 0.10 (against α-amylase) and 5.60 ± 0.10, 2.70 ± 0.10 and 2.90 ± 0.10 µM (against α-glucosidase), correspondingly. On the other hand, analogs bearing substituent(s) of either a bulky nature (-Br) or that are incapable of forming hydrogen bonds (-CH₃) were found to lower the inhibitory potentials. In order to investigate the binding sites for synthetic analogs and how they interact with the active areas of both targeted enzymes, molecular docking studies were also conducted on the potent analogs. The results showed that these analogs adopted many important interactions with the active areas of enzymes. The precise structure of the newly synthesized compounds was confirmed using several spectroscopic techniques as NMR and HREI-MS.

Synthesis, in vitro cholinesterase inhibition, molecular docking, DFT and ADME studies of novel 1,3,4-oxadiazole 2-thiol derivatives

A sequence of 1,3,4-oxadiazole 2-thiol derivatives bearing various alkyl or aryl moieties was designed, synthesized, and characterized by modern spectroscopic methods to yield 17 compounds ( 6a - 6q ) which were screened for acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes in search of 'lead' compounds for the treatment of Alzheimer disease (AD). The compounds 6q, 6p, 6k, 6o, and 6l showed inhibitory capability against AChE and BChE, with IC 50 values ranging from 11.730.49 to 27.360.29 µM for AChE and 21.830.39 to 39.430.44 µM for BChE, inhibiting both enzymes within a limited range. The SAR ascertained that the substitution of the aromatic moiety had a profound effect on the AChE and BChE inhibitory potential as compared to the aliphatic substitutions which were supported by the molecular docking studies. In silico ADME studies reinforced the drug-likeness of most of the synthesized molecules. These results were additionally supplemented by the molecular orbital analysis (HOMO-LUMO) and electrostatic potential maps got from DFT calculations. ESP maps expose that on all structures, there are two potential binding sites conquered by the most positive and most negative districts.

Blue honeysuckle extracts retarded starch digestion by inhibiting glycosidases and changing the starch structure

Blue honeysuckle rich in anthocyanins can inhibit starch-digesting enzyme activity. This study evaluated the inhibitory effect and mechanism of blue honeysuckle extract (BHE) on glycosidases (α-amylase and α-glucosidase). BHE was a mixed glycosidase inhibitor with an IC₅₀ of 2.36 ± 0.14 and 0.06 ± 0.01 for α-amylase and α-glucosidase, respectively. Fourier transform infrared (FTIR) spectroscopy, multi-fluorescence spectroscopy, and isothermal titration calorimetry (ITC) confirmed that BHE caused the secondary structure change and static fluorescence quenching of glycosidases, and the interaction was an enthalpy-driven exothermic reaction. Molecular docking proved that the main anthocyanin monomers in BHE interacted with glycosidases through hydrogen bonds and van der Waals forces. Moreover, BHE changed the starch structure and prevented starch from being digested by glycosidases. In vivo, BHE and starch-BHE complexes effectively slowed postprandial hyperglycemia. This research provided a theoretical basis for BHE in antidiabetic healthy food research and development.

Bio-Oriented Synthesis of Novel (S)-Flurbiprofen Clubbed Hydrazone Schiff’s Bases for Diabetic Management: In Vitro and In Silico Studies

A new series of (S)-flurbiprofen derivatives 4a–4p and 5a–5n were synthesized with different aromatic or aliphatic aldehydes and ketones to produce Schiff’s bases and their structures were confirmed through HR-ESI-MS, ¹H, and ¹³C-NMR spectroscopy. The α-glucosidase inhibitory activities of the newly synthesized compounds were scrutinized, in which six compounds 5k, 4h, 5h, 4d, 4b, and 5i showed potent inhibition in the range of 0.93 to 10.26 µM, respectively, whereas fifteen compounds 4c, 4g, 4i, 4j, 4l, 4m, 4o, 4p, 5c, 5d, 5j, 5l, 5m, 5n and 1 exhibited significant inhibitory activity with IC₅₀ in range of = 11.42 to 48.39 µM. In addition, compounds 5g, 5f, 4k, 4n, and 4f displayed moderate-to-low activities. The modes of binding of all the active compounds were determined through the molecular docking approach, which revealed that two residues, specifically Glu277 and His351 are important in the stabilization of the active compounds in the active site of α-glucosidase. Furthermore, these compounds block the active site with high binding energies (−7.51 to −3.36 kcal/mol) thereby inhibiting the function of the enzyme.

Biology-oriented drug synthesis and evaluation of secnidazole esters as novel enzyme ınhibitors

The identification of novel compounds that can inhibit physiologically and metabolically important drug targets or enzymes has prime importance in medicinal chemistry. With this aim, a range of secnidazole esters 1-30 were synthesized under the heading of biology-oriented drug synthesis by the 1,1'-carbonyldiimidazole-mediated coupling reaction between secnidazole and varyingly benzoic acid derivatives. All compounds were screened for inhibitory activity against human carbonic anhydrase (hCA) I and II, acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glucosidase. The results indicate that all the synthesized compounds showed potent inhibitory activities against all targets, as compared to the standard inhibitors, revealed by IC₅₀ values. K_i values of the secnidazole derivatives 1-30 for hCA I, hCA II, AChE, BChE, and α-glucosidase enzymes were obtained in the ranges of 47.37-190.74, 44.38-198.21, 12.14-68.37, 8.04-61.53, and 7.78-45.91 nM, respectively. To assess the enzyme-ligand interactions, the optimized most active compounds 2, 3, 8, 9, 14, 17, and 23 were subjected to molecular docking studies with modeled AChE, BChE, hCA I, hCA II, and α-glucosidase enzymes, where several important and key interactions were monitored with amino acid residues of each target enzyme.

Inhibitory Potential of New Phenolic Hydrazide-Hydrazones with a Decoy Substrate Fragment towards Laccase from a Phytopathogenic Fungus: SAR and Molecular Docking Studies

Laccase from pathogenic fungi participates in both the delignification and neutralization of phytoantibiotics. Furthermore, it interferes with the hormone signaling in plants and catalyzes melanization. Infections of these pathogens contribute to loss in forestry, agriculture, and horticulture. As there is still a need to expand knowledge on efficient defense strategies against phytopathogenic fungi, the present study aimed to reveal more information on the molecular mechanisms of laccase inhibition with natural and natural-like carboxylic acid semi-synthetic derivatives. A set of hydrazide-hydrazones derived from carboxylic acids, generally including electron-rich arene units that serve as a decoy substrate, was synthesized and tested with laccase from Trametes versicolor. The classic synthesis of the title inhibitors proceeded with good to almost quantitative yield. Ninety percent of the tested molecules were active in the range of K_I = 8–233 µM and showed different types of action. Such magnitude of inhibition constants qualified the hydrazide-hydrazones as strong laccase inhibitors. Molecular docking studies supporting the experimental data explained the selected derivatives’ interactions with the enzyme. The results are promising in developing new potential antifungal agents mitigating the damage scale in the plant cultivation, gardening, and horticulture sectors.

Synthesis of indole derivatives as diabetics II inhibitors and enzymatic kinetics study of α-glucosidase and α-amylase along with their in-silico study

In this study, we have investigated a series of indole-based compounds for their inhibitory study against pancreatic α-amylase and intestinal α-glucosidase activity. Inhibitors of carbohydrate degrading enzymes appear to have an essential role as antidiabetic drugs. All analogous exhibited good to moderate α-amylase (IC50 = 3.80 to 47.50 μM), and α-glucosidase inhibitory interactions (IC50 = 3.10-52.20 μM) in comparison with standard acarbose (IC50 = 12.28 μM and 11.29 μM). The analogues 4, 11, 12, 15, 14 and 17 had good activity potential both for enzymes inhibitory interactions. Structure activity relationships were deliberated to propose the influence of substituents on the inhibitory potential of analogues. Docking studies revealed the interaction of more potential analogues and enzyme active site. Further, we studied their kinetic study of most active compounds showed that compounds 15, 14, 12, 17 and 11 are competitive for α-amylase and non- competitive for α-glucosidase.

Exploring biological efficacy of novel benzothiazole linked 2,5-disubstituted-1,3,4-oxadiazole hybrids as efficient α-amylase inhibitors: Synthesis, characterization, inhibition, molecular docking, molecular dynamics and Monte Carlo based QSAR studies

In an effort to explore a class of novel antidiabetic agents, we have made an effort to synergize the α-amylase inhibitory potential of 1,3-benzothiazole and 1,3,4-oxadiazole scaffolds by combining the two into a single structure via an ether linkage. The structure of synthesized benzothiazole clubbed oxadiazole derivatives are established by different spectral techniques. The synthesized hybrids are evaluated for their in vitro inhibitory potential against α-amylase. Compound 8f is found to be the most potent with a significant inhibition (87.5 ± 0.74% at 50 μg/mL, 82.27 ± 1.85% at 25 μg/mL and 79.94 ± 1.88% at 12.5 μg/mL) when compared to positive control acarbose (77.96 ± 2.06%, 71.17 ± 0.60%, 67.24 ± 1.16% at 50 μg/mL, 25 μg/mL and 12.5 μg/mL concentration). Molecular docking of the most potent enzyme inhibitor, 8f, shows promising interaction with the binding site of biological macromolecule Aspergillus oryzae α-amylase (PDB ID: 7TAA) and human pancreatic α-amylase (PDB ID: 3BAJ). To a step further, in-depth QSAR studies show a significant correlation between the experimental and the predicted inhibitory activities with the best R_validation²= 0.8701. The developed QSAR model can provide ample information about the structural features responsible for the increase and decrease of inhibitory activity. The mechanistic interpretation of the structure-activity relationship (SAR) is done with the help of combined computational calculations i.e. molecular docking and QSAR. Finally, molecular dynamic simulations are performed to get an insight into the binding mode of the most potent derivative with α-amylase from A. oryzae (PDB ID: 7TAA) and human pancreas (PDB ID: 3BAJ).

Substituted Benzimidazole Analogues as Potential α-Amylase Inhibitors and Radical Scavengers

Benzimidazole scaffolds are known to have a diverse range of biological activities and found to be antidiabetic and antioxidant. In this study, a variety of arylated benzimidazoles 1-31 were synthesized. Except for compounds 1, 6, 7, and 8, all are new derivatives. All compounds were screened for α-amylase inhibitory, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. In vitro screening results revealed that all molecules demonstrated significant α-amylase inhibition with IC50 values of 1.86 ± 0.08 to 3.16 ± 0.31 μM as compared to standard acarbose (IC50 = 1.46 ± 0.26 μM). However, compounds showed significant ABTS and DPPH radical scavenging potentials with IC50 values in the range of 1.37 ± 0.21 to 4.00 ± 0.10 μM for ABTS and 1.36 ± 0.09 to 3.60 ± 0.20 μM for DPPH radical scavenging activities when compared to ascorbic acid with IC50 values of 0.72 ± 0.21 and 0.73 ± 0.05 μM for ABTS and DPPH radical scavenging potentials, respectively. Structure-activity relationship (SAR) was established after critical analysis of varying substitution effects on α-amylase inhibitory and radical scavenging (ABTS and DPPH) potentials. However, molecular docking was also performed to figure out the active participation of different groups of synthetic molecules during binding with the active pocket of the α-amylase enzyme.

Novel cinnamic acid magnolol derivatives as potent α-glucosidase and α-amylase inhibitors: Synthesis, in vitro and in silico studies

In this study, twenty novel cinnamic acid magnolol derivatives were synthesized, and screened for their anti-hyperglycemic potential. All synthesized compounds exhibited good to moderate α-glucosidase and α-amylase inhibitory activities with IC₅₀ values: 5.11 ± 1.46-90.26 ± 1.85 µM and 4.27 ± 1.51-49.28 ± 2.54 µM as compared to the standard acarbose (IC₅₀: 255.44 ± 1.89 μM and 80.33 ± 2.95 μM, respectively). Compound 6j showed the strongest inhibitory activity against α-glucosidase (IC₅₀ = 5.11 ± 1.46 µM) and α-amylase (IC₅₀ = 4.27 ± 1.51 µM). Kinetic study indicated that compound 6j was reversible and a mixed type inhibitor against α-glucosidase and α-amylase. In silico studies revealed the binding interaction between 6j and two enzymes, respectively. Finally, cells cytotoxicity assay revealed that compound 6j showed low toxicity against 3 T3-L1 cells and HepG2 cells.

Synthesis of azachalcones, their α-amylase, α-glucosidase inhibitory activities, kinetics, and molecular docking studies

Diabetes being a chronic metabolic disorder have attracted the attention of medicinal chemists and biologists. The introduction of new and potential drug candidates for the cure and treatment of diabetes has become a major concern due to its increased prevelance worldwide. In the current study, twenty-seven azachalcone derivatives 3-29 were synthesized and evaluated for their antihyperglycemic activities by inhibiting α-amylase and α-glucosidase enzymes. Five compounds 3 (IC50 = 23.08 ± 0.03 µM), (IC50 = 26.08 ± 0.43 µM), 5 (IC50 = 24.57 ± 0.07 µM), (IC50 = 27.57 ± 0.07 µM), 6 (IC50 = 24.94 ± 0.12 µM), (IC50 = 27.13 ± 0.08 µM), 16 (IC50 = 27.57 ± 0.07 µM), (IC50 = 29.13 ± 0.18 µM), and 28 (IC50 = 26.94 ± 0.12 µM) (IC50 = 27.99 ± 0.09 µM) demonstrated good inhibitory activities against α-amylase and α-glucosidase enzymes, respectively. Acarbose was used as the standard in this study. Structure-activity relationship was established by considering the parent skeleton and different substitutions on aryl ring. The compounds were also subjected for kinetic studies to study their mechanism of action and they showed competitive mode of inhibition against both enzymes. The molecular docking studies have supported the results and showed that these compounds have been involved in various binding interactions within the active site of enzyme.

Identification of potential TNF-α inhibitors: from in silico to in vitro studies

Tumor Necrosis Factor Alpha (TNF-α) is a pleiotropic pro-inflammatory cytokine. It act as central biological regulator in critical immune functions, but its dysregulation has been linked with a number of diseases. Inhibition of TNF-α has considerable therapeutic potential for diseases such as cancer, diabetes, and especially autoimmune diseases. Despite the fact that many small molecule inhibitors have been identified against TNF-α, no orally active drug has been reported yet which demand an urgent need of a small molecule drug against TNF-α. This study focuses on the development of ligand-based selective pharmacophore model to perform virtual screening of plant origin natural product database for the identification of potential inhibitors against TNF-α. The resultant hits, identified as actives were evaluated by molecular docking studies to get insight into their potential binding interaction with the target protein. Based on pharmacophore matching, interacting residues, docking score, more affinity towards TNF-α with diverse scaffolds five compounds were selected for in vitro activity study. Experimental validation led to the identification of three chemically diverse potential compounds with the IC₅₀ 32.5 ± 4.5 µM, 6.5 ± 0.8 µM and 27.4 ± 1.7 µM, respectively.

Dihydropyridines as potential α-amylase and α-glucosidase inhibitors: Synthesis, in vitro and in silico studies

Dihydropyridine derivatives 1-31 were synthesized via one-pot solvent free condition and screened for in vitro against α-amylase and α-glucosidase enzyme. The synthetic derivatives 1-31 showed good α-amylase inhibition in the range of IC50 = 2.21 ± 0.06-9.97 ± 0.08 µM, as compared to the standard drug acarbose (IC50 = 2.01 ± 0.1 µM) and α-glucosidase inhibition in the range of IC50 = 2.31 ± 0.09-9.9 ± 0.1 µM as compared to standard acarbose (IC50 = 2.07 ± 0.1 µM), respectively. To determine the mode of binding interactions of synthetic molecules with active sites of enzyme, molecular docking studies were also performed. Different spectroscopic techniques such as 1H, 13C NMR, EI-MS, and HREI-MS were used to characterize all the synthetic compounds.

Biology-oriented drug synthesis (BIODS), in vitro urease inhibitory activity, and in silico studies on ibuprofen derivatives

Novel ibuprofen derivatives 1-19 including ibuprofen hydrazide 1, and substituted thiourea derivatives 2-19 were synthesized and characterized by EI-MS, FAB-MS, HREI-MS, HRFAB-MS, ¹H-, and ¹³C-NMR spectroscopic techniques. The synthetic molecules 1-19 were examined for their in vitro urease inhibition and were found to display a diversified degree of inhibitory potential in the range of IC₅₀ = 2.96-178 μM as compared to the standard thiourea (IC₅₀ = 21.32 ± 0.22 μM). Out of nineteen, thirteen derivatives 2-4, 6, 7, 9, 11-15, 17, and 18 demonstrated remarkable inhibitory activity with IC₅₀ values of 2.96 ± 1.11 to 16.1 ± 1.07 μM, compound 5 exhibited moderate inhibition with IC₅₀ value of 37.3 ± 0.41 μM, whereas, compounds 1, 8, and 10 demonstrated weak inhibition against urease enzyme. Almost all structural features are participating in the activity; however, limited structure-activity relationship was discussed on the basis of different structural features, i.e., different functional groups and their positions at aryl part. In addition, molecular docking study was performed in order to understand the ligands binding interactions with the active site of urease enzyme.

An Insight of Alpha-amylase Inhibitors as a Valuable Tool in the Management of Type 2 Diabetes Mellitus

BACKGROUND

Among the millions of people around the world, the most prevalent metabolic disorder is diabetes mellitus. Due to the drawbacks which are associated with commercially available antidiabetic agents, new therapeutic approaches are needed to be considered. Alpha-amylase is a membrane- bound enzyme which is responsible for the breakdown of polysaccharides such as starch to monosaccharides which can be absorbed.

METHODS

We searched the scientific database using alpha-amylase, diabetes, antidiabetic agents as the keywords. Here in, only peer-reviewed research articles were collected which were useful to our current work.

RESULTS

To overcome the research gap, the alpha-amylase enzyme is regarded as a good target for antidiabetic agents to design the drug and provide an alternate approach for the treatment of type 2 diabetes mellitus. Basically, alpha-amylase inhibitors are classified into two groups: proteinaceous inhibitors, and non-proteinaceous inhibitors. Recently, non-proteinaceous inhibitors are being explored which includes chalcones, flavones, benzothiazoles, etc. as the potential antidiabetic agents.

CONCLUSION

Herein, we discuss various potential antidiabetic agents which are strategically targeted alpha-amylase enzyme. These are having lesser side effects as compared to other antidiabetic agents, and are proposed to prevent the digestion and absorption of glucose leading to a decrease in the blood glucose level.